Spoofing communications signals or navigation signals involves broadcasting counterfeit or false communications or navigation signals, such as global positioning system (GPS) navigation signals or other type navigation signals in an attempt to deceive a communications or navigation device or receiver. The spoofed or spoofing signals may be structured to resemble expected communications signals or normal navigation signals. Spoofing may also involve rebroadcasting genuine signals captured elsewhere or at a different time. These spoofed signals may be modified or altered in such a way as to provide false information or data or to cause a navigation device or receiver to estimate its position to be somewhere other than where the navigation device is actually located. One common form of a GPS spoofing or navigation spoofing attack, commonly referred to as a carry-over attack, begins by broadcasting signals synchronized with the genuine signals received by a target receiver. The power of the counterfeit signals is then gradually increased and the navigation device is drawn away from the genuine signals.